Dimmer switches

[diyuseless]

I have a one way dimmer switch which has two black wires coming from it and it insists, as it is a brass front, I connect an earth wire to the screw on the back of the plate.The light switch has at the top the number 1, with a blue and red cable going into it. Opposite that is a 2 with two red cables. and at the bottom a yellow cable.

It also has two green/yellow cables going into the metal back box.

I am assuming this is a two way switch and therefore the one way dimmer will not be suitable for the job.

Also, any advice on the earth cable would be appreciated as I do not know whether I am to just connect the earth cables from the box or need to supply other cable. attach

 

[breezer]

could you enlighten us more with regard to these 2 black wires, are you saying they came attached to the switch?

and also it does sound like you have a one way switch and you wanty two way, also note my signature

 

[ban-all-sheds]

I have a one way dimmer switch which has two black wires coming from it and it insists, as it is a brass front, I connect an earth wire to the screw on the back of the plate.The light switch has at the top the number 1, with a blue and red cable going into it. Opposite that is a 2 with two red cables. and at the bottom a yellow cable.

That's an unconventional way of wiring it, but it'll work fine - see the reference topic for details of 2-way wiring.

It also has two green/yellow cables going into the metal back box.

As they should

I am assuming this is a two way switch and therefore the one way dimmer will not be suitable for the job.

Why do you only "assume"? - Isn't there another 2-way switch somewhere else that controls the same light? But anyway- if it is a 1-way dimmer, it won't be suitable as a replacement for a 2-way switch. And even if you do get a 2-way dimmer, if you turn the light on with the other switch it'll come on to the brightness setting of the dimmer switch, so you may still have to walk over there...

Also, any advice on the earth cable would be appreciated as I do not know whether I am to just connect the earth cables from the box or need to supply other cable. attach

I expect the switch has an earth terminal on it? Connect the two existing earths to that, plus a third bit of green/yellow sleeved cable running to the box.